A U of I graduate student is in custody for the death of his estranged girlfriend. Urbana police arrested 29-year-old Yongfei Ci at a motel in Champaign.

Investigators report Ci is the man believed to be responsible for the death of a 25-year-old University of Illinois student.

Urbana police said officers were called shortly after 11 am Friday to the One South apartment complex on North Lincoln Avenue. That's where a woman had run into the courtyard and reported that her 25-year-old roommate had been killed.

Police report 'there was a roommate who had been in the apartment at the time. The woman had been restrained. She broke free and came out into the courtyard where she notified police of the incident.'

The suspect was located by police using cellphone technology. Ci surrendered without incident, according to police.

According to an Urbana police press release, Ci forced his way into the apartment and locked the victim's roommate in the bathroom. The roommate was left uninjured.Police have not released the name of the victim nor how she died. An autopsy is pending.

A press release from Urbana Police stated Ci is a sixth-year Ph.D. student in math at the U of I.University of Illinois police issued Illini alerts about the off-campus homicide and put out the suspect's name and description of his car.

Anyone with information on this incident is asked to call Urbana police at 217-384-2320 or Crimestoppers at 217-373-8477.